Electrical contact members.



H. V. S. TAYLOR.

ELECTRICAL CONTACT MEMBERS.

APPLICATION FILED AUG.30, 1916. 1,232,625, Patented July 10, 1917.

Non-arcing mefa/ such as P/af/num, lriaiumef'cr Pefracfory mefa/ such 4 as Tungsfen.

WITNESSES:

I VE I Horace l cgel or.

'- AToRE coatings and films,

.many attempts HORACE V. S. TAYLOR, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRICAL CONTACT MEMBERS.

Original application filed January 21, 19 1 6, Serial-No. 73,494. Divided and this application filed August 30,

1916. Serial No. 117,668.

To all whom it may concern:

Be it known that I, HoRAonV. S. TAYLOR, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have in-- vented a new and useful Improvement in Electrical Contact Members, of which the following is a specification, this application being a division of applicationSerial No. 73,494, filed January 21, 1916.

My-invention relates to contact members adapted for use in electrical apparatus such as relays, regulators, switches and the like, and it has for its object to provide a pair of cooperating contact members that shall be durable and comparatively inexpensive, and which, in operation, shall not be subjected to pitting or burning and consequent roughening.- It is also my object to provide cooperating contact members which 'will not stick or fuse together during their operation and which shall remain clean and free from surface oxidation and from other insulating whereby good contact is insured when the members are brought into engagement.

Make and break contact members for relays, regulators and similar devices have heretofore been commonly made of platinum, iridium, platinum-iridium alloys and other metals of the platinum type. These metals make very satisfactory contact members, but on account of their high cost, have been made to provide a suitable inexpensive substitute. Refractory metals of the type of tungsten and molybdenum have been proposed for this purpose but have not been found satisfactory for, use in cooperating pairs because these metals are readily oxidizable under the conditions encountered in the use of make and break contact members. and their oxids are non-conductors of. electricity.

contact members,

Consequently, when both contact members of, a cooperating pair-are composed of tungsten or molybdenum, a film of oxid forms upon the member constituting the anode and prevents or interferes with the making of reliable and effective electrical contact between the members. 'It has also been" proposed to employ silver, for of the but it has been found that, when such members are subjected to severe service, the member constituting the cath- Specification of Letters Patent.

, platinum,

be either tungsten,

' use of arc-suppressin Patented July 10,1917.

ode is apt to pit badly and to become rough because of the relatively low fusing point of silver and its inherent tendency to produce arcs.

In my copending application for Letters Patent, filed January 21,1916, Serial No. 73,494, of which the present application is a division, I have described and claimed a specific modification of my invention, ac-

cording to which a contact member of tungsten, molybdenum or an equivalent refractory' metal is used in cooperation with a metal of the platinum type.

The single figure of the accompanying drawing is illustrative of' my invention and shows a cooperating pairof. contact members 1 and 2 of which the anode 1 is provided with an active working face 3 of iridium, platinum-iridium alloy or the like, while the cathode 2 is provided with an active working face 4 of refractory metal of -the tungsten type which may molybdenum or other equivalent metal.

The use of platinum anode contact members instead of the silveranodes specifically claimed. in my above-mentioned copending application is sometimes preferable when the contact members are to be subjected to severe service or where non-arcing contact metals are requiredu For example, in'interrupters for the ignition apparatus of internal combustion engines, it is important that arcing be avoided and it is impracticable to make shunt connections or similar devices. Un er such circumstances, I prefer to employ platinum anodes in spite of the with si ver. I I

' The combination herein set forth hasbeen 1 found to be very effective and reliable and it is obviously much less expensive than when platinum or iridium is used for both eater cost of platinum as compared I as may be substltuted therefor in cooperaproduce effective pairs Q V I contactmembers. The contact resistance is low and the contact members'do not become insulatedfrom each other,

In general, it is preferable to employ 5 tungsten or molybdenum as the cathode, and the platinum,

material as the anode. however, sults in some cases, for example, in the 'interr'upters of ignition apparatus.

In the appended claims, the expression metal of the latinum type is intended to include not only platinum ltself, but iridium, platinum-iridium alloys, osmium, and other chemically inert and non-arcing metals which may be substituted for platinum in -The relations may,

the contact members herein described. The.

iridium or other non-arcingbereversed with satisfactory reexpression refractory metal of the tungsten type is intended to include tungsten, mo-

denum, and such other refractory metals tion with platinum to of contact members. I desire that the claims be construed to cover these and all Y other modifications which fall fairly within their scope.

I claim as myinvention:

bers, the active wor 'ng faces of which are composed, respectively, of metal of the plati- 'In testimony whereof, I 1 1. A pair of 006 crating contact mem- -a cathode having an active refractory metal of the tungsten type.

contact members,

num type and of refractory metal of the tungsten type.

' 2. A pair of cooperating contact members comprising an anode havin an active working face of metal of the,p atinum type and working face of 3. A pair of cooperating the active working faces of which are composed, respectively, ofuplatinum and of a refractory metal .of the tungsten typ e 4:. A pair of cooperating contact members A comprising an anode having an active working face of platinum and a cathode having an active working face composed of a refractory metal of the tungsten type.

5. A pair of cooperating contact members, the active working faces of which are composed, respectively, of platinum and of tungsten.

6. A pair of cooperating contact members comprising an anode having an active working face of platinum and a cathode having an active working face of tungsten.

7 A- pair of mated vibratory contacts, one of tungsten and the other of platinum.

subscribed my 4 HORACE V. s. TAYLOR.

have hereunto 

